About hardware, 1 xonar u1 audio station, About hardware 2.1 – Asus Xonar U1 User Manual
Page 10: Xonar u1 audio station

ASUS Xonar U1
2.
About Hardware
2.1
Xonar U1 Audio Station
2
1
3
R
No Item
Description
1
Microphone jack
Connect your external PC microphone to this 3.5mm jack for
voice input. Built-in high-quality Microphone pre-amplifier.
Line Input jack
Connect analog devices like MP3 players, CD players,
music synthesizers and other line-level sound sources to this
3.5mm jack for audio recording or processing.
2
Headphone/Front
Output jack
Connect your headphones or 2/2.1 channel speakers to this
jack. For multi-channel speaker systems, connects to the
front left/right input on the powered speakers.
S/PDIF Output jack
Optical S/PDIF output jack. Connects to an external digital
decoder or digital speaker systems, Home Theater systems,
AV receivers for outputting digital audio including PCM,
Dolby Digital, WMA-Pro, etc.
3
Volume knob
Rotate this knob to adjust the volume.
Hot button
Short push this knob to mute the music, and long push to
turn to the Hi-Fi mode.
4
LED indicator
Red light --> Mute
blue light --> Hi-Fi mode
Flashing blue light --> User mode
4